Liquid crystal display devices are widely being applied in our daily lives and work, in which a liquid crystal panel is significantly relevant to a display effect of each of the liquid crystal display devices, including its viewing angle, brightness degrees, colors and so on.
A production process of the mainstream thin film transistor liquid crystal device (TFT-LCD) is primarily implemented by exposures and masks. A liquid crystal display device is a passive matrix light-emitting device, which comprises a color filter substrate and a thin film transistor array substrate. Although a color film on array (COA) design has been developed in recent years, the production process of the COA is more complicated and has a lower yield. Therefore, a structure of separating the color filter substrate from the thin film transistor array substrate is still dominating the mainstream technology in the LCD field.
The thin film transistor array substrate primarily comprises a data line, a scan line, a thin film transistor switch, a pixel electrode, a peripheral circuit and so forth; while the color filter substrate comprises a black matrix (BM), and a trichromatic light-filtering layer having red (R), green (G) and blue (B). Since the alignment state of liquid crystal molecules in the liquid crystal display are controlled by changing a voltage driving an integrated chip, with determination of switching a backlight source, different colored lights are formed through the light-filtering layers so that different colors are formed therefrom to make the liquid crystal display rendering vivid and bright frames. Thus, the color filter is a critical component of the liquid crystal display.
Fabricating a conventional color filter requires at least five masks as following steps of: forming black matrices by sputtering a resin layer on a glass substrate; forming a red light-filtering pattern on an opening portion between the black matrices; repeating the above steps to sequentially form a green light-filtering pattern and a blue light-filtering pattern; and finally forming a photo spacer (PS) layer. Moreover, a multi-domain vertical alignment (MVA) LCD is accomplished with needs of using six masks in: forming the black matrices; forming a red light-filtering pattern; forming a green light-filtering pattern; forming a blue light-filtering pattern; forming a common electrode layer; and forming a photo spacer layer.
Meanwhile, to accomplish the red light-filtering pattern, the green light-filtering pattern and the blue light-filtering pattern, using three different masks is essential as well as sequentially executing three exposures and three developments. As shown in FIG. 1 to FIG. 3, a first mask 11 is used to form a red light-filtering pattern 110. After that, a second mask 12 is used to form a green light-filtering pattern 120. Then a third mask 13 is used to form a blue light-filtering pattern 130. Since in the conventional art the red light-filtering pattern, the green light-filtering and the blue light-filtering must be formed by three different masks, this would cost higher and take longtime. Therefore, it is necessary to provide a method for fabricating a color filter substrate in order to solve the problems of the prior art.